"""
 day19.py - advent of code for day 19

 programming workshop class exercise

"""

data = open('input19.txt').readlines()
#print(data)
print("The number of lines is ", len(data))
print("The 0'th line : '{}'".format(data[0]))

# starting point:
row = 0
col = 0
while data[row][col] == ' ':
    col = col + 1
print("Starting at row={}, col={} there is a '{}'".format(
      row, col, data[row][col]))
direction = 'down'
steps = 0

def move(row, col, direction):
    """ return new row, col, direction after making a move """
    row += {'down': 1, 'up': -1, 'right': 0, 'left': 0}[direction]
    col += {'down': 0, 'up': 0, 'right': 1, 'left': -1}[direction]
    if data[row][col] == '+':
        # change direction
        if direction == 'up' or direction == 'down':
            if data[row][col+1] == ' ':
                direction = 'left'
            else:
                direction = 'right'
        else:
            if data[row+1][col] == ' ':
                direction = 'up'
            else:
                direction = 'down'
    return (row, col, direction)

letters = []
here = data[row][col]

while here != ' ':
    if here.isalpha():
        letters.append(here)
    (row, col, direction) = move(row, col, direction)
    here = data[row][col]
    steps += 1
    
print("The answer to part 1 is {}".format(letters))
print("The answer to part 2 is {}".format(steps))